Control for pressing machines



. Sept. 5, 1939. I NECKEL 2,171,593

CONTROL FOR PRESSING MACHINES Filed Oct. 26, 1937 2 Sheets-Sheet 1 l3 F|G.-l

G K l ax INVENTOR EDMUND N. NECKEL ATTORNEYS P 1939- E. N. NECKEL 2,171,593

CONTROL FOR PRESSING MACHINES Filed Oct. 26, 1937 2 Sheets-Sheet 2 gob 3{ -36 FIG.- 9

INVENTOR EDMUND NECKEL BY W 4 i RNEYs Patented Sept. 5, 1939 UNiTED STATES PATENT OFFICE CONTROL FOR PRESSING MACHINES Application October. 26, 1937, Serial No. 171,073

11 Claims.

This invention relates to improvements in' control mechanism. for power pressing machines.

An object of the present invention is to provide an actuating device for a power control member in a press wherein the control member is moved by the device to fully operated position which limits the movement of the device if all of the parts are rigid, but the device is provided with a yieldable part permitting a shortening of the device as it is further actuated to a holding position.

My improved control device is particularly useful where the control member for the press power means includes a toggle movable over center to a holding position and wherein the toggle is provided with a yieldable part permitting toggle shortening as it passes over center while the control member remains in fully operated position.

My improvement has particular application to two-hand control means for a press power means wherein a toggle connected with the control memher is movable short of its center position until the press is safely closed and during which preliminary movement the toggle is free to break to an unoperated position and after the press is safely closed, movement of the toggle over center is enabled by the press parts and the toggle is permitted to shorten as it moves over center so that the control member may remain in a fully operated position. This is a particularly valuable improvement where the control member is a fluid valve having an exhaustport which is closed when the valve is in fully operated position and wherein my improved control device permits the exhaust Valve to remain fully closed at all times when the press is being operated so that no leakage of pressure fluid occurs.

Other advantages of my invention will appear in the accompanying specification and drawings and the essential features will be set forth in the claims.

In the drawings, Fig. 1 is an end elevation of a pressing machine equipped with my improved control mechanism and showing in full lines the open position, in dot-dash lines the safe closed position, and in dash lines the fully closed position of the press parts; Fig. 2 is a diagrammatic view of the control mechanism of Fig. 1 corresponding to open position of the press; Fig. 3 is a sectional view along the line 33 of Fig. 2; Fig. 4 is a partial sectional View along the line 44 of Fig. 3; Fig. 5 is a diagrammatic view like Fig. 2 showing the control mechanism corresponding substantially to the dot-dash position of the press parts in Fig. 1; Fig. 6 is a similar diagrammatic view of the control mechanism in fully operated position and corresponding to the closed or clash line position of the press in Fig. 1; Fig. 7 is a partial sectional view similar to Fig. 3 showing the toggle knuckle in a displaced posi- 5 tion; Fig. 8 is a fragmental plan view showing a modified form of toggle knuckle structure; Fig. 9 is a sectional view taken on the line 99 of Fig. 8; while Fig. 10 is a view similar to Fig. 9 showing the toggle knuckle in displaced position. 10

While my invention is applicable to many types of pressing machines, it is particularly applicable to garment and laundry presses, one type of which is indicated in Fig. l as comprising a frame [0 supporting a pressing bed H and pivotally supporting a head lever I2 adapted upon oscillation to carry the head i3 into and out of engagement with bed I I. Head movement is provided by way of toggle I4 actuated by fluid motor [5. This motor has a piston l5a and a piston rod [5b connected with the toggle M. A spring I6 normally returns the head to open position when the motor is deenergized. The supply of motive fluid to motor I 4 is preferably provided by means of a safety two-hand control mechanism. These mechanisms are well known, some types embodying a pair of valves each controlled by one hand of the operator, at other times comprising enabling control member actuating means operable by one hand when enabling parts are simultaneously actuated by the other hand of the operator. I have chosen a form of two-hand control to illustrate the present invention and com.- prising manuals I1 and [8 so spaced at the front of the press that the finger grips Ila and Mia are accessible to the operator at all points sufliciently spaced to require both hands of the operator for their coincidental actuation. The manuals l1 and i8 are connected by means of toggles l9 and 20 respectively, with opposite ends of an equalizer bar 2|. In the form shown the toggle links l9a and 20a are integral with the manuals and the links I91) and 201) are separate members. A pin 22 pivotally connected intermediate the ends of the equalizer bar and suitably guided in the frame is adapted to engage the stem 230 for actuating the valves in casing 23 so as to supply pressure fluid through conduits 24 and 25 to motor [5. While I have shown a valve directly controlling the fluid supply from supply conduit 24, it will be Well understood by those skilled in this art that a pilot valve might be interpolated here which by its actuation would in turn actuate a main control valve. The valves in casing 23 comprise an inlet valve 23a here ment of the parts to the position in Figs. 5 and 6,

the inlet port is opened and exhaust valve 236 is closed. If this exhaust port is not fully closed by the shoulder 23!) there will be leakage of pressure fluid at this point.

The arrangement between the manuals and control valve is such that if one manual is operated alone there will be insufficient movement of pin 22 to actuate the valves in casing 23. However, upon movement of both manuals as indicated in Fig. 5 to a position Where toggles E9 and 26 are short of center or straight line position, pin 22 engages valve stem 23c, opening the inlet valve 23a and completely closing the exhaust valve 231). In this position of the parts, toggles l6 and 26 will be broken outwardly if either manual is released due to pressure on the valve parts either by the incoming pressure fluid or spring 26 and also by additional means later described. Preferably a movable stop 21 is provided limiting the movement of the manuals to the position of Fig. 5 until the press is safely closed. This requires a hand of the operator on each manual until the press is safely closed so that injury to the hands is impossible.

Means is provided for removing stop 21 when the press is safely closed. In the form shown the stop 2'! is part of a bellcrank 28 pivotally mounted on the press frame and actuated by a rod 29 which passes through a slotted bracket Ma on toggle 14. The rod 29 is provided with collars 26a and 29b and the stop 21 is biased to the position of Figs. 2 and 5 by spring 30. When the press reaches "safe closed position the bracket i la engages collar 29a causing clockwise rotation of bellcrarik 28 as seen in Fig. 1, thus removing stop 21 and'permitting actuation of manuals l1 and 18 to the fully actuated and maintained position of Fig. 6 Here both toggles Hi1 and 20 have moved over center to break inwardly where they rest against a fixed and limiting stop 3|. With the toggles in this position the valves in casing 23 are held actuated and the press remains closed until one of the manuals is returned to the position of Fig. 2 permitting spring l6 to open the press.

The mechanism which I have thus far describedis not broadly new but I have incorporated therein a valuable improvement. Referring to Figs. 5 andG, it will be noted that in each 'case the exhaust valve port is tightly closed with theshoulder 23b against its coacting seat. It will be noted also that toggles I9 and 26 have moved from a position breaking outwardly over center to a position breaking inwardly. It will be obmit this movement of an over-center device while maintaining the exhaust valve fully closed so that there will be no leakage of pressure fluid. It all of the parts were rigid then the exhaust valve 231) would reach fully closed position as the toggles l9 and 20 went over center and in the maintained position of Fig. 6 the exhaust port would be open so that leakage would be constant while the press was closed.

A suitable form of yielding part for the purpose above set forth is shown in Figs. 3, 4 and 7. Here the toggle arm 26a is provided with a cupshape end 32 and the toggle arm 2017 has a similar cup-shape end 33. These ends are normally alined as shown in Fig. 3 and have mutually engaging faces, one concave and one convex as shown at 34. The bores within the cups are square as shown in Fig. 4. A plug 35 has a square portion entering the bore of the member 33 and provided with a threaded portion 35a which has threaded engagement with a helical spring 36. Fitting within the bore of member 32 is a square block 3! having a portion 31a in threaded engagement with the other end of spring 36. Integral with plug 31 is a threaded stem 31b extending outside the member 32 and there supplied with suitable adjusting and lock nuts 38. When the parts are assembled and adjusted the distance between portions 35a and 31a is such as to place spring 36 under tension.

The device just described provides a yieldable fit for the toggle knuckle '20, the operation of which isa's follows: When the manuals are moved from the position of Fig. 2 to that of Fig. 5, spring 36 is wound in a direction to give a bias tending to break the toggle 2i] outwardly if manual i8 is released. The threads at 35a and 31a are both right-hand so that the spring is held firmly when placed under this winding torque. When it is attempted to move the toggle 2i] from the position of Fig. 5 over center to the position of Fig.6, the point 231) being firmly held, the yieldable knuckle is displaced as shown in Fig. 7 lifting the coacting cam parts at 34 out of engagement as shown. After the toggle is moved over center to the position of Fig.6, the coacting cam parts at 34 return the yieldable knuckle pivot or spring 36 to a straight line position. When in the position of Fig. '6, manual I8 is released, the parts will remain in that position because, while spring 36 is wound in a direction tending to'break the toggles outwardly, the tension of spring 36 in the direction of the spring axis holds the coacting seats 34 in-engagement so that the knuckle may not be broken simply by the torque stored in spring 36. Instead to return the parts from the position of Fig. 6 to that of Fig. 2, manual operation of the manual I8 is necessary.

During motion of the toggle mechanism back and forth across dead center between its intermediate position, Fig. 5, and its fully-operated position, Fig. 6, both of the toggles vary in length, shortening as they move toward dead center and lengthening as they move away from it. That is to say, while the effective or over all length of each toggle between the pivotal'mounting of its link I90. or 200. on the frame and the pivotal connection of its link l9b 'or 20b to the equalizing bar 2| remains the same, the relation of the two links of each toggle to each other is'more or less inclinedor in coincidence with the shortening and lengthening ofthe toggle as referred to.

While I'have explained the arrangement of a yieldable knuckle on toggle 20 it will be understood that toggle IS'may beconstructed'in exactly the same manner withthe exception that the threaded portions corresponding to 35a and 3'la-and'the winding of the helical spring will be in the left-hand direction to 'cause the parts to operate properly. Nevertheless if sufficient displacement as indicated at Fig. 7 is provided in toggle 20, then toggle I9 might .have a plain knuckle and the device would operate.

In the modification of Figs. 8, 9 and 10, parts having similar arrangements and function are designated by reference characters similar to those already used. In this case, however, it will be noted that the coacting seats 39 are squared Ofi for direct sliding movement when the displacement occurs as in Fig. 10 in a toggle shortening direction. The spring 36 in this case when first assembled is under a tension in the direction of the axis of the spring as in the first form described. Here the lateral displacement of spring 36 tends to return the parts from the position of Fig. 10 to the normal position of Fig. 9. However, I have provided in addition spring means which is loaded when the knuckle is displaced so as to return the knuckle to its normal position after the toggle passes over center. This spring means comprises a bracket c holding a reciprocating pin 49 having at its inner end a rigid collar 4| between which and the bracket 20c is compressed a spring 42. The nuts 43 limit the extended position of pin 40. This pin engages the member 32 in such a manner that as the toggles pass over center and the knuckle is displaced as shown in Fig. 10, spring 42 is loaded so that as the toggle passes over center the power stored in spring 42 helps to return the member 32 to the position of Fig. 9 where the knuckle pivot is again in straight line position.

What I claim is:

1. In a pressing machine having coacting relatively movable pressing members and power means for causing a pressing action between them, a control member for said power means movable to a fully operated power supply position beyond which it cannot be moved, actuating means for said control member including an overcenter toggle device having one toggle end free to move, an operative connection between said movable end and said control member arranged to move the latter to fully operated position when said device is short of center position, and said device having a yieldable toggle part permitting toggle-shortening movement of said device as it moves over center while said control member remains in fully operated position.

2. In a pressing machine having coacting relatively movable pressing members and power means for causing a pressing action between them, a control member for said power means movable to a fully operated power supply position beyond which it cannot be moved, actuating means for said control member including an over-center toggle device having one toggle end free to move, an operative connection between said movable end and said control member arranged to move the latter to fully operated position when said device is short of center position, and said device having a yieldable toggle part permitting toggle-shortening movement of said device as it moves over center while said control member remains in fully operated position, said yieldable part being constructed and arranged to return said control member from short of center position to unoperated position.

3. In a pressing machine having coacting relatively movable pressing members and power means for causing a pressing action between them, a control member for said power means movable to a fully operated power supply position beyond which it cannot be moved, actuating means for said control member including an over-center toggle device having one toggle end free to move, an operative connection between said movable end and said control member arranged to move the latter to fully. operated position when said device is short of center position, and said device having a yieldable toggle part permitting toggle-shortening movement of said device as it moves over center while said control member remains in fully operated position, said device and yieldable part being constructed and arranged to hold said device on either side of center position.

4. In a pressing machine having coacting relatively movable pressing members and fluid actuated power means for causing a pressing action between them, a control valve for said power means having a shoulder engaging a fluid exhaust port when in fully operated position, actuating means for said valve including spaced safety manuals both of which must be actuated coincidentally to operate said valve, said actuating means including at least one toggle connection between said manuals and said valve, said connection being free to move endwise, said actuating means being arranged to move said valve to fully operated position by endwise movement of said toggle short of center position, said actuating means being arranged to hold said toggle overcenter and said valve fully operated, and said toggle having a part permitting toggle shortening, whereby said toggle may be moved over center while said shoulder engages said exhaust port.

5. The combination of claim 4 and including means for preventing movement of said toggle over center until said pressing machine reaches a safe closed position.

6. In a pressing machine having coacting relatively movable pressing members and fluid actuated power means for causing a pressing action between them, a control valve for said power means having a shoulder engaging a fluid exhaust port when in fully operated position, actuating means for said valve including a pair of spaced safety manuals, an equalizer bar having an operative connection with said valve, toggles one at each end of said bar and connected to one of said manuals, said toggles being extensible endwise and jointly controlling said bar, manual operation being adapted to move said toggles from unoperated position over center to operated position, movable stop means limiting said toggles to a short-of-center position adapted to hold said valve fully operated, fixed stop means limiting said toggles to an over-center position adapted to hold said valve fully operated, means for removing said movable stop means when said pressing machine reaches a safe closed position, and at least one of said toggles having a yieldable knuckle connection permitting a shortening of said toggle as it moves over center.

7. The combination of claim 6 in which said knuckle connection comprises a helical spring pivot adapted to be loaded by toggle movement in a manner to bias the associated toggle toward unoperated position, and means resisting toggle shortening.

8. In a pressing machine having relatively movable coacting pressing members and power means for causing relative approach movement of said members, a control member for said power means having a power supply position beyond which it can not be moved, means for actuating said control member comprising an equalizer bar operatively associated with said control member, spaced safety manuals operatively connected one with each end of said equalizer bar, the parts being so arranged as to require coincidental actuation of both manuals to move said control member to supply position, at least one of said operative connections between said manuals and said bar comprising a toggle having two links pivotally connected at a knuckle, said toggle being short of straightened position when said control member is in supply position, said knuckle having a yieldable construction including a helical spring connecting adjacent ends of said links and having anchorages on said links normally alined at the pivot point of said knuckle, said link ends being constructed to permit lateral movement of one of said anchorages out of pivotal alinernent with the other to permit movement of said toggle to overstraightened position, there being means effective when said ends are out of alinement for returning them to alinement, and said operative in overconnections including said toggle straightened position being adapted to hold said control member in supply position.

9. The combination of claim 8 including interfitting coacting parts on adjacent ends of said links, the part on one end being concave and the part on the other end. being convex, said parts being so placed that they tend to return the anchorages to pivotal alinement.

10. The combination of claim 8 wherein said last'named means comprises a spring-pressed plunger, the spring whereof is loaded by movement of said anchorages out of alinement.

11. The combination of claim 8 including means preventing rotation of said anchorages relative to said links, whereby said spring is loaded in torsion by rotation of said links about said knuckle pivot.

EDMUND N. NECKEL. 

